Hyperactive behavior (HB) is a vexing problem for a large number of children with and without a formal diagnosis of attention-deficit/hyperactivity disorder (ADHD). Although the causes of HB are poorly understood, one such cause may be primary sleep disorders; the small subset of children seen at sleep centers often have HB that resolves when a sleep disorder is identified and treated. Arising from this observation, the long-term objective of this application is to examine the impact of undiagnosed sleep disorders on HB in children. The research plan starts with a cross-sectional survey of 1000 parents at a general pediatrics clinic to test for associations between HB and symptoms of sleep disorders in children aged 2 to 14 years. Subjects thus found to be hyperactive will be tested to establish the frequency of sleep disorders. A randomized controlled clinical trial will then be performed to determine whether HB improves when children+s sleep disorders are treated. Finally, the cohort of children originally identified as being free of HB will be reassessed 4 years later to determine which symptoms of sleep disorders might predict later development of HB.